Cargo B tail strike at BRU.

[Ctail]

Anyone has more info on this one?
Happened on 27 oct PM while departing, took off, dumped fuel and came back to BRU.

[747Comet]

Yes, I heard about this yesterday. Cargo B has been phoning around asking for ACMI.

Does any one know how bad the strike was and how long the aircraft will be out of action.

[Rainboe]

Wow! That must have been an amazing rotation on take-off. I'm inclined to think the over-rotation was once airborne, I don't think you could do this sort of damage with the wheels still in contact. Over-rotation damage I have seen has been much further forward just aft of the upsweep. Likely explanation- serious miscalculation of weight?

[ETOPS]

Looks similar to the Singapore tailstrike "down under" a little while ago........

[TopBunk]

On first sight, and not being a structural engineer, it would appeared to have damaged the rear pressure bulkhead. If that is the case and it is an old airframe, I find it hard to believe that it is a viable proposition to restore it to service.

[747Comet]

The flight they were operating was only about 30000kgs so it might have been an over rotatation?

With CBA now aog and CBB still in check, the -400 now delayed till Jan 2009 could Cargo B be in trouble:confused:

[glhcarl]

On first sight, and not being a structural engineer, it would appeared to have damaged the rear pressure bulkhead. If that is the case and it is an old airframe, I find it hard to believe that it is a viable proposition to restore it to service.


The APB is forward of the vertical stabilizer and there is evidence that the skin has been scraped in this area. But without being able to see how much skin deformation there is in this area, it is hard to tell APB damage by looking at external damage.

[Rainboe]

it would appeared to have damaged the rear pressure bulkhead.
Looks like it to me. The rest is superficial, but that would be prohibitively expensive. One of the Documentary channels is running a program about changing a 767 rear pressure bulkhead. It's a big difficult job. I still can't imagine clobbering it like that.

[BelArgUSA]

The pressure bulkhead location coincides exactly with the leading edge of the tailplane... So look at the picture, and take your conclusions. If it is the case, it will be an expensive repair.
xxx
:eek:
Dark contrails

[BelArgUSA]

I have seen a few 747 with tail strike damage.
But none as bad as this one.
xxx
Generally, the tail strike is limited to the belly (skin) area.
Here it appears that it is a serious "over-rotation" problem.
After the belly scraped, continued rotation further into APU area.
xxx
I shall say nothing.
:E
Happy contrails

[Ex Cargo Clown]

Surely this is either a load shift, a gross weight miscalculation or a huge loadsheet and trim problem.

No sane pilot is going to over-rotate that badly unless something is very amiss and there's nothing they can really do to prevent a strike.

[Mercenary Pilot]

Surely this is either a load shift, a gross weight miscalculation or a huge loadsheet and trim problem.That was my thoughts. To me it looks like the tail was dragged for a fair ol' distance.

http://www.luchtzak.be/forums/download/file.php?id=89&t=1&sid=06110f9a4263387b1dfe91596633aa20

[MaxBlow]

I thought that weight and balance systems where installed on all dedicated 747 freighters. This one used to be ex-AF according to my listings.
Loadshift would be a good reason. A loadsheet must have been wrong by about 100t or more to get results like this.

I don't think it'll be repaired as it would be very expensive to fix this scratch and cargob has reportedly been in rather serious financial troubles lately.

Guess the crew is invited to the office to answer some questions.:ouch:

[Rainboe]

That sort of loadshift is more likely to induce an extremely rapid conclusion to the flight. If there was a gross error of loading data, the takeoff performance would be wrong. Happened at AKL to another 747 with similar results.

[Ex Cargo Clown]

Maybe not a loadshift then, more a loadsheet problem, and reported CG% out of kilter with the actual loading of the aircraft. Heavy pallets loaded further aft than they should be would cause a few problems to say the least.

[greuzi]

Eyewitnesses who know pointy end from blunt suggest 200m plus at the scraping attitude, and a real concern it was not going to get airborne.

[greuzi]

Another broken -200 freighter. Been a busy year.

[744rules]

-no loadsheet error (all wgts correct, loaded according to loadplan)
-cg well within limits (zfw 25pct mac)
-payload 107.5t
-no load shift as a/c full
-fob 99t
-all frt was reweighed. result 300kg difference

[BelArgUSA]

Generally, a 747F or SF is approximately 156,000 to 160,000 kg BOW.
So with 99 tons of fuel, and payload 108 tons, the T/O weight was some 365,000 which makes it a heavy aircraft.
xxx
That aircraft Max TO weight, is either a 377,800 or a 371,900 kg.
:ok:
Happy contrails

[ETOPS]

When flying with new co-pilots on the 747-400 I always give them a simple rule about V speeds. When leaving the flight deck, after landing, set the speed in the MCP to zero. That forces the next crew to set something in that box before take-off. SOP is to put the ball park V2 figure based on expected TOW which can be extracted from the table on the checklist. I also advise a gross error check before take-off. Thus - is 144kts a sensible V2 for 370T ?? No it's approach speed left over from the previous sector...........

[Flamin_Squirrel]

Interesting! I thought that V-Speeds were entered into the FMC though? How does the MCP speed come into play during take off?

[FEclassic]

probally that happened; wrong weight will give wrong speeds (low) and thrust setting (low), and you have to fly at Vr> tailstrike
:= what about X-checking the T/O calculations between pilots

[Dr. Feelgood]

What about on older "fashioned" way......calculate speeds according tables in QRH, then verify and crosscheck them with the speeds calculated by the FMC?

[ETOPS]

then verify and crosscheck them with the speeds calculated by the FMC?
Of course - I'm using a belt and braces approach. You should see me and altimetry :eek:

[Dr. Feelgood]

As expected, the typical and quite stupid PPRUNE remark:ugh:

Very usefull input ETOPS:ok:!

Happy flying

Doc.

[Semu]

Interesting picture. I was always told that if we over rotated heavy we would strike more forward, and if empty, further aft, due to strut compression. :confused:

[BelArgUSA]

Flying 747-200, I always leave the cockpit with "bugs" and "numbers" zeroed.
The 5 airspeed bugs are pressed together.
The dial is set to lowest value.
Altimeter bugs and selectors, same story...
Transponder - reset to 2000.
xxx
Every qualified pilot should have "approximate speeds" in their head.
Takeoff or landing, heavy and light weight.
I know approximate EPRs, N1 or FF...
Approximate CG pitch trim setting should be known too.
xxx
:rolleyes:
Happy contrails

[Intruder]

V2 rule of thumb (747 Classic): Take first 2 digits of gross weight in Tonnes. Double it. Put a 1 in front of it. That's V2 for Flaps 20.

Example: 327 Tonnes. Round to 330. Double 33 for 66. Put 1 in front for 166.

Accurate to about 3 KIAS.

[GlueBall]

Wonder what the insurance deductable may be if gross crew incompetence is proven? :{

[Onions]

The same......

[stilton]

Flamin Squirrel,

For departure, the speed bug on the mode control panel (mcp) is set to V2, on the 757 / 767 the flight directors will guide you to V2 plus 15 knots (faster if you rotate slower than optimum) after rotation.

I have not flown the 744 but I would imagine they follow the same procedure.

[sarah737]

I was told the crew made an error of 100 tons when calculating take off performance.

[YouNeverStopLearning]

The damage in the picture would seem to suggest that, after initial rotation didn't lift the a/c, the "pull" was continued, maybe in fear as the end of the TORA approached.

you can see the marks on the lower area starting approx where Boeing would have had their "oak log" positioned for their minimum unstick speed test-flight t/o's.

the rear extensive damage is consistent with extended contact AND loading. this would have continued until the aircraft reached an a/s that allowed it fly away... in this case before it hit anything in the net t/o flightpath.

anyone know if the crew increased/firewalled the power when it was obvious that.......?

A word of humility here: everyone makes mistakes, thankfully most of us don't find ours on PPRUNE... although i do check! lol lol

[Tediek]

What is happening with the aircraft? For repair or W/O?

[tttoon]

It's been (or being) repaired, but I don't know if it will return to Cargo B service as OO-CBC (744) is coming in the next few months.

[EMIT]

Don't know about (possibly updated) -200 avionics, but if .....

an FMC is available and ...
FMC figures are used for V-speeds, ....

then, as often indicated by Boeing,

... if Zero Fuel Mass is entered in the Gross Mass line,

you make the largest error possible, all your fuel mass is not taken into account (was the fuel mass for this a/c reported as some 100 tons?)

and the result may look like what you see in the pictures.

Of course, other types of errors may produce the same result, but FMC people, watch out and use sensible cross checks as given before by other posters.

[Airbubba]

I was told the crew made an error of 100 tons when calculating take off performance.

... if Zero Fuel Mass is entered in the Gross Mass line,

you make the largest error possible, all your fuel mass is not taken into account (was the fuel mass for this a/c reported as some 100 tons?)

and the result may look like what you see in the pictures.

This 100 ton (or 100K lbs) error has occured many times in large aircraft, on takeoff and landing, sometimes causing scrapes, sometimes causing a mishap. I have a friend who flew out of the miscalculation with a slow rotation and a very long runway.

Some ACARS software won't let you check the weather until the fuel is entered, some folks put in zero to get the box off the initialization page. Obviously, I've never been crazy about this technique.

Some places teach a rough setup with expected weights, finetuned later with the actual data. Other places are adamant that you should wait until you get a final loadsheet, paper or electronic, to enter anything.

Flying 747-200, I always leave the cockpit with "bugs" and "numbers" zeroed.


I went to the same schoolhouse in MIA and still have that habit a couple of jobs later.